U.S. singer Jason Mraz performs during his concert "Tour Is A Four Letter Word" in Hong Kong. (June 24, 2012) Photo Credit: AP

Before working on his new album, "Love Is a Four-Letter Word" (Atlantic), Mraz realized it was time to set some new goals for his music. After all, his previous album had yielded two monster hits, "Lucky" and "I'm Yours," which now hold the record for the longest run in the history of the pop charts, an astonishing 76 weeks in 2008 and 2009.

For years, Mraz tried to make his mark in the music industry by balancing clever, humorous lyrics one minute and thought-provoking, powerful ballads the next. Following "I'm Yours," though, Mraz had nothing left to prove to anyone -- except maybe himself.

"In my life, I always try to balance the sacred and the silly," says Mraz, calling from a tour stop in West Palm Beach, Fla. "In my shows, that comes up a lot more. If I play two or three serious songs in a row, I'll always break the tension with a humorous song. On this album, though, I definitely wanted to take it seriously."

Mraz says he wondered if he really had a follow-up to "We Sing. We Dance. We Steal Things." in him. "With the success of the last album, I received enough acclaim and financial reward," he says. "Why would I even have to continue? Things were perfect. But I remembered quickly that success isn't those things. Success is how I feel when I'm playing music. And I didn't want to give up on myself or the music that's in me. I became very serious with the project because I wanted it to be great. I guess I also wanted to prove to myself that I could keep going."

He says love became the topic for "Love Is a Four-Letter Word" because he began writing it after ending a relationship. "The stuff in the music was the medicine I was taking, the medicine of thought, in order to get me to the next level -- songs like 'Living in the Moment,' 'I Won't Give Up,' '93 Million Miles,' 'The Woman I Love,' which is about understanding how to love and hold space for others," Mraz says. "I really wanted love to be the topic because that's where I was most confronted in my life. I had success in music, but why hadn't I ever mastered the relationship? The only relationship I'd mastered was the one I had with me, while I was kind of being selfish with my dream. I really wanted to focus on that topic and it was transformative. It was really, really helpful."

Mraz says he feels different about the world now. "I guess I was a bit confronted by the rewards and the financial gain and all that," he says. "I felt very undeserving, and I ended up giving a lot away -- a lot of material things, a lot of money. I felt like I needed to start over."

He spent time in the Gulf of Mexico on cleanup duty after the Deepwater Horizon oil spill. He went to Antarctica to learn about climate change with Al Gore. He announced his early support for President Barack Obama's re-election. And on his current tour, Mraz has even targeted single-use plastic water bottles by partnering with Brita filters to offer free water and encourage his fans to switch to reusable glass bottles at the concerts. "It saves money and it's better for the environment," he says. "I didn't want to travel around the country leaving piles of garbage in my wake. That's not how I live at home. That's not how I want to live on tour."

The changes have served Mraz well. Not only did the new album debut at No. 2, his highest chart position ever, it also drummed up interest for his biggest tour ever, in arenas and amphitheaters, including a stop at Nikon at Jones Beach Theater Saturday. "I was surprised when I heard I'd be playing places this big," he says, laughing. "But that's why I have a great manager. If it wasn't for him, I'd never have left the coffee shops. There's no way I'd have played the Royal Albert Hall or these amphitheaters and arenas."

Mraz says he was worried about maintaining the same level of intimacy with crowds in the larger spaces, but he hopes to fix that through video screens and sound systems. "The voice is clear, the songs are true, we don't really have to worry about none of that," he says. "When the lights come up, everyone's still there and everyone's still singing. It is the greatest honor for a songwriter to hear anybody sing their song. To hear it done by a mass of people? You can't beat it."